Edit: Concerning the SMGs it is pretty clear what they need to adress. Each SMG has the same spread and damage stats, only differentiated by recoil and ROF. That makes little sense to me, since it gives the MP40, Sten and MP34 no real niche. They are just as inaccurate as the Suomi at range. I have no idea why they went away from the BF4 system with individual spread increase values, which would solve most of these issues.

I think that's your answer. More than twice the HRec on the Suomi compared to the MP34 stock (the MP40's base is even lower than the MP34's base), four times as much when taking the reduction specs for both. While it shows ADSStandRecoilUp as "0" in the data, I think that's just an error. Pretty sure it does have vertical recoil.

Yes, I know, it still does not compare. It is the spread that kills the low ROF SMGs, not the recoil. They all have the same base spread, min and max and the same SIPS. When I look at my stats, I see the following. For a 30% higher ROF with the Suomi, I get 2,7% less accuraccy and a 15% increase in kpm. That is my dataset. This is further diminished by the the 50 round magazine where you are more inclined to just hose down a street and that you are more prone to overshoot a target with a higher rate of fire. What they should have done is to adjust the SIPS according to the ROF, like they did in BF4. Look at the SIPS of the PP-2000, that is a third of the MP34's.

I'm going purely by the stats in this post here, as I haven't yet bought BFV. I can't say for sure what my numbers would thus look like.

What I CAN say, however, is that my BF3 and BF4 stats never showed a good correlation between weapon RoF/accuracy and the hit percentage I end up achieving. (e.g. my most used automatic weapon in BF4, the AKU-12 sits at 20,79% accuracy, while the P90 is at 21,82% and the ACW-R is at 20.54%; all three weapons used for 1200-1900 kills).
The big factor that I suspect behind this surprising similarity of accuracies is not that the gun isn't more accurate or that I just aim worse with lower RPM guns. I think that it's mainly the engagement distances I choose to accept.

If I run the AKU-12 or UMP-45 I will try to engage or return fire on targets further away, while with the ACW-R and P90 I would try to escape and try to close the gap to reengage from closer range. Thus it seems logical to me that I would not end up with a much higher hitrate despite the gun being technically more accurate.

Memorable quotes not taken yet:

Of course, this ignores the non-constant cross-sectional first moment of area across the chest as well as non-constant material properties of the boob; it would be difficult to perform a more detailed analysis (as in, I'd have to have a shape function AND I'd need to derive a function for elastic modulus as a function of lateral breast coordinate) but whatever. It's 2am and I'm lazy.

You should also answer this question I had posed in that thread: Would you be willing to pay your surgeon more if he was going to use a chainsaw for the opening incision of surgery? Clearly using a chainsaw isn't truly suited for surgery but that doesn't really matter. If he's "skilled" enough to be able to use the wrong tools of the trade, he should be rewarded for that skill right?

I'm going purely by the stats in this post here, as I haven't yet bought BFV. I can't say for sure what my numbers would thus look like.

What I CAN say, however, is that my BF3 and BF4 stats never showed a good correlation between weapon RoF/accuracy and the hit percentage I end up achieving. (e.g. my most used automatic weapon in BF4, the AKU-12 sits at 20,79% accuracy, while the P90 is at 21,82% and the ACW-R is at 20.54%; all three weapons used for 1200-1900 kills).
The big factor that I suspect behind this surprising similarity of accuracies is not that the gun isn't more accurate or that I just aim worse with lower RPM guns. I think that it's mainly the engagement distances I choose to accept.

If I run the AKU-12 or UMP-45 I will try to engage or return fire on targets further away, while with the ACW-R and P90 I would try to escape and try to close the gap to reengage from closer range. Thus it seems logical to me that I would not end up with a much higher hitrate despite the gun being technically more accurate.

Yep, this is a sensible thought, and I would agree that with the F2000 I would try to cut some corners and decrease the average engagement distance. BFV SMGs however, which are the only weapons I've played, I largely play them all the same. I use the Suomi at the same ranges I would take engagements with the Sten, and my perception is that I do better even there. There could be other things at play, like panicking opponents when they get hit by a hose of bullets instead of a slow trickle. Is there something like an aim punch when you get hit?
But I think mostly it is that for me, and this might be personal, the recoil does not scale well with the spread. The Suomi definitely feels more natural than the Sten.

@NoctyrneSAGA
Very true, but for if my bursts with the Sten and MP40 are longer (too long likely) than with the Suomi, it might still be in favour of the high ROF weapon. As said, it might be a personal thing.

I hope you all are taking advantage of crouch/prone and their 30%/50% vertical recoil reduction; it definitely helps guns like the Suomi, but I find it's the accuracy-focused guns like the Sten and MP 40 that really benefit from it. Don't sleep on single-shot mode either, you get some substantial recoil reductions there.

And noting both of these things, the M1907 is now my favourite Assault gun.

How does it work? I thought Spread Decrease would set in right at the moment you have stopped firing, could fire another round, but do not. So if I shoot my PP-2000 to an accumulated spread and let it reset for a a splitseconds and start shooting again my spread will start at base spread again.
So if I tend to burst my Sten for say 8 rounds, because this is where I feel the gun is getting too uncontrollable, I will have accumulated additional 2.0 spread, which will take a certain time to reset to base. My bursts with the Suomi might only be 5 bullets long, since recoil is higher, so my spread increase is at 1.25, meaning that on average, I will spend more timer at lower spreads with the Suomi. Now this is very dependant on range, but while I do use the Suomi like a BF4 weapon, tapfiring and such, I definitely feel the spread on the Sten, because I might not even stop firing with such a low recoil.
In any case, I think that nobody would disagree on scaling SIPS according to the firerate of the weapon, is a good idea to make the low ROF SMGs more competeable. Right now the long-range option of the MP34 is just a grand overexeggeration, regardless of how many videos DRUNKKZ3 puts out.

I mean I might be slighlty wrong on this mechanic-wise, but my experiences from the playtests, release and stats confirm my initial assumption of SMGs having a problem with accuracy that the other weapons do not have.

BFV updated spread to be continuous. It fixes the problem that ROF had on a weapon's spread recovery.

Faster weapons had their recovery kick in faster before which is kind of counterintuitive.

Continuous SDEC changes that by giving faster ROF weapons less time between shots to recover spread.

Now all the weapons can share similar values and ROF implicitly regulates their spread recovery.

Ah okay, but my initial assumptions were applicable for BF4, right? So you are saying that since a weapon with firerate of 900 would have Spread Decrease kick in earlier, it would profit more from SDec than a 600 ROF weapon, correct? Now all SDEC kicks in at the same timeframe for all SMGs? I might be daft, but I am just trying to understand the data.